Self-sucking silencer for motor cars generally



Don afa fo/0- Nov. 29, 1927..

D. MOLA SELF SUCKING SILENCER FOR MOTOR CARS GENERALLY Original Filed Aug. 27, 1925 Patented Nov. 29, 1927.

PAT'ENT loFFlcE.

DONATO HOLA, OF ROME, ITALY.

SELF-SUCKING SILENCER FOR :MOTORv CARS GENRALLY.

Application med Angust 27, 1925, serial No. 52,785, and in Italy August 29, 1924. Renewed onwber'aO, 1927.

It is well known that by furnishing the exhaust tube of internal combustion engines and explosive motors with special self-sucking silencers the efficiency of the motors is increased with a fremarkable economy of motor fuel.

There is, however, the drawback that the noise is greater than that producedby common silencers when the motor is running with closed exhaust.

The improvements according to this invention have the object of removing nearly all the noise while at the same time the effieiency of the motor is still more increased.

Said improvements are illustrated in the accompanying drawings, in which Fig. 1 shows the longitudinal section of a silencer.

Fig. 2 shows a cross section on the line 1-1 of Fig. 1.

The improved silencer comprises an upper pointed conical-shaped diaphragm -D-, the base of which is provided with a ange tiwith openings -d1-` communicating with a first expansion chamber -A-. Said flange is perpcndicularly turned to form the cover of the silencer and the tube F- connected to the exhaust tube. Moreover the part forming the cover is provided with holes in which the tubes -H communicating at the top with the external air, are engaged, and after running through the whole length of the chamber -A- join the interior of the lower or depression chamber -E-. In the inside of the casing forming the chamber -A- there are arranged concentrically a second cylinder forming the chamber -B- and a tube C joined to the diaphragm -D- and on the side of this diaphragm the tube C- is provided Wit-h holes /iof different diameter. Said tube C- runs through the lower diaphragm -D1 and ends nearly t* the mouth of the depression chamber The diaphragm -D1- is spheroidally shaped and provided with openings -gfor the flow of the gases from the first chamber A* into the second -B- from which they pass through the holes -45 of the tube -C- in the interior of the same, and are ejected outside. Said diaphragm Operation.

The burnt gases entering the silencer from the tube -F- strike the diaphragm -D-, which is pointed enough to weaken the shock and facilitate the How into the irst chamber -A-, Where the gases expand and their volume reduced owing to the very large peripherical surface of the chamber exposed to the external air and to the fact'of the tubes -II through which a fresh air draught passes at their outlet into the chamber -B- across the openings gprovided in the diaphragm -D1- their pressure is much reduced. The gases by expanding again change their direction and flow into the central tube -C- through the holes 7lprovided near the upper diaphragm -D- to be rapidly sucked into the depression chamber -E- owing to the depression eiiect produced in this chamber by the iowing of the fresh air guided through the tubes -I[-.l

In cons uence of the above described operation ethe residual noise of the gases, owing to their kinetic energy being diminished during their expansions and changes of direction, is completely removed by the opposed diametral directions of the holes -c'- opening out into the central tube `C- so that the sound Waves are reciprocally destroyed.

Having now particularly described and ascertained my said invention and the manner in which the same is to be performed, what I claim and desire to secure by Letters Patent is:

An exhaust silencer for internal combustion engines comprising 'in combination, a casi-ng having concentric expansion chambers, a conically shaped diaphragm at the intake end of the casing, said diaphragm closing one end of the inner expansion chamber and having a flange portion provided with orifices to admit exhaust gases into the outer expansion chamber, a perforated spheroidally shaped diaphragm at the opvposite end of the innerexansion chamber, or the admission of om the outer to the inner expansion c amber, tubes open at -5 one end to atmosphere and at the other end to a space beyond the casing, a second casing comprising a depression chamber at the discharge end of said first casing into which the said tubes discharge air, and an outlet i e arran ed coaxiall of saidrst cas' 15 sure end og said pipe 3being provided openin to admit gases from the said inner expanslon chamber and the other end of .sald pipe discharging into said second casln. 20

n testimony whereof I have hereunto signed m name.

y MOLA, DONATO. 

